Air conditioning apparatus

ABSTRACT

An air conditioning apparatus includes a plurality of heat source apparatuses having heat source apparatus side heat exchangers and compressors, one or a plurality of indoor units having flow rate control devices and indoor unit side heat exchangers, at least two main pipes for performing connection-piping between a plurality of heat source apparatuses and one or a plurality of indoor units, a tubular distributor for branching the refrigerant from the main pipe flowing from the inlet to a plurality of outlets to distribute into a plurality of heat source apparatuses, and connection piping for connecting the plurality of heat source apparatuses and distributor respectively. Among a plurality of heat source apparatuses, the distributor is fixedly disposed at a specified position and in a specified direction against one heat source apparatus.

TECHNICAL FIELD

The present invention relates to an air conditioning apparatus using arefrigeration cycle, more particularly to an arrangement of adistributor and the like installed for distributing refrigerant andrefrigerator oil when a plurality of heat source apparatuses (heatsource side units) are provided.

BACKGROUND ART

An air conditioning apparatus is provided that can individuallyarbitrarily perform cooling and heating operations. (For example, referto Patent Document 1) In such an air conditioning apparatus, arefrigerant flows in the same direction in a plurality of refrigerantpiping from a heat source apparatus to a plurality of indoor units (loadside units). That is, a high-pressure refrigerant is output from theheat source apparatus and a low-pressure refrigerant returns to the heatsource apparatus. Thereby, there is one heat source apparatus and sincethe refrigerant returns to the heat source apparatus always through asingle piping from a plurality of indoor units, the refrigerant returnsto the heat source apparatus in the proper quantity. In addition,hereinafter high or low pressure is not specified in relation to areference pressure but represented as a relative pressure by such aspressurization by a compressor 11 and a refrigerator pass control byeach throttle device. Further, it is the same for high and lowtemperatures.

The refrigerant oil discharged from the compressor in the heat sourceapparatus returns through the indoor unit to the heat source apparatus,however, since such refrigerator oil all returns to a single heat sourceapparatus, problems such as a depletion of the refrigerator oil hardlyoccur.

[Patent Document 1] Japanese Examined Patent Application No. H7-52045

DISCLOSURE OF INVENTION Problems to be Solved by the Invention

For example, when there are many indoor units and much more capabilityis required for the heat source apparatus side, air conditioning isperformed by pipe-connecting a plurality of heat source apparatuses.Thereby, for example, a plurality of heat source apparatuses areconnected in parallel, the refrigerant in each heat source apparatus isjoined to be supplied to the indoor unit side, and the refrigerant andrefrigerator oil from the indoor unit side are branched to bedistributed to each heat source apparatus. Then, it is necessary todistribute them to each heat source apparatus with an appropriate amountin accordance with an operation condition thereof.

In the case when the refrigerant is in a gas-liquid two-phase conditionand the refrigerator oil is mixed and included in a gas refrigerant, aliquid refrigerant and refrigerator oil are not necessarily dividedaccording to the same ratio as a distribution ratio of the gasrefrigerant. Especially under such a condition that a gas flow ratefalls, a liquid becomes a laminar flow to flow along an inner surface ofpiping and be subjected to gravity and centrifugal forces. Therefore, itis not easy to determine the degree of distribution of liquids. When aliquid distribution rate changes dependent on such as an installationstatus of distribution means and the like, it is possible that some heatsource apparatuses may run short of the refrigerant and return amount ofthe refrigerator oil. Nevertheless, installation of distribution meanshas been subjected to, for example, convenience of arrangement of aplurality of heat source apparatuses at an installation site.

In order to solve the above problems, the purpose of the presentinvention is to provide an air conditioning apparatus capable ofeffectively distributing the refrigerant and refrigerator oil into aplurality of heat source apparatuses.

Means for Solving the Problems

An air conditioning apparatus according to the present inventionincludes a plurality of heat source apparatuses having a heat sourceapparatus side heat exchanger and a compressor, one or more indoor unitshaving a flow rate control device and an indoor unit side heatexchanger, at least two main pipes for pipe-connecting between aplurality of heat source apparatuses and one or more indoor units, atubular distributor for branching a refrigerant from a main pipe flowingfrom an inlet into a plurality of outlets to distribute into a pluralityof heat source apparatuses, and connection piping for connecting aplurality of heat source apparatuses and the distributor respectivelyand fixedly disposes the distributor against one heat source apparatusamong the plurality of heat source apparatuses at a predeterminedposition in a predetermined direction.

EFFECT OF THE INVENTION

According to the present invention, since a distributor for distributinga refrigerant to a plurality of heat source apparatuses is fixedlydisposed at a predetermined position against one heat source apparatus,a stable refrigerant distribution can be performed according to apredetermined supposed distribution by the arrangement in considerationof the effect of gravity and each heat source apparatus (especially oneheat source apparatus).

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram showing an entire configuration and the like of anair conditioning apparatus 1 according to Embodiment 1.

FIG. 2 is a diagram showing a refrigerant flow at an all heatingoperation according to Embodiment 1.

FIG. 3 is a diagram showing a refrigerant flow at a cooling-dominantoperation according to Embodiment 1.

FIG. 4 is a diagram showing a refrigerant flow at a heating-dominantoperation according to Embodiment 1.

FIG. 5 is a diagram showing an installation status (arrangement) ofmeans focusing on a distributor 50.

FIG. 6 is an enlarged diagram of FIG. 5 with the distributor 50 beingthe center.

FIG. 7 is a diagram showing an entire configuration and the like of anair conditioning apparatus 1 according to Embodiment 2.

FIG. 8 is a diagram showing a refrigerant flow at an all heatingoperation according to Embodiment 2.

FIG. 9 is a diagram showing a refrigerant flow at a cooling-dominantoperation according to Embodiment 2.

FIG. 10 is a diagram showing a refrigerant flow at a heating-dominantoperation according to Embodiment 2.

FIG. 11 is a diagram showing an entire configuration of the airconditioning apparatus 1 according to Embodiment 3.

REFERENCE NUMERALS

-   1 air conditioning apparatus-   10A, 10B heat source apparatus-   11A, 11B compressor-   12A, 12B four-way switching valve-   13A, 13B heat source apparatus side heat exchanger-   14A, 14B accumulator-   15-1A, 15-1B first check valve-   15-2A, 15-2B second check valve-   15-3A, 15-3B third check valve-   15-4A, 15-4B fourth check valve-   16-1A, 16-1B first manual opening and closing valve-   16-2A, 16-2B second manual opening and closing valve-   16-3A, 16-3B third manual opening and closing valve-   17A, 17B fixing sheet metal-   18A, 18B electromagnetic opening and dosing valve-   19A, 19B flow rate control valve-   20 a, 20 b, 20 c indoor unit-   21 a, 21 b, 21 c indoor unit side heat exchanger-   22 a, 22 b, 22 c indoor unit side flow rate control device-   30 relay-   31 first branched part-   32, 33 association part-   34 a, 34 b, 34 c first opening and closing valve-   35 a, 35 b, 35 c second opening and closing valve-   36 second branched part-   37, 38 association part-   39 a, 39 b, 39 c first relay check valve-   40 a, 40 b, 40 c second relay check valve-   41 gas-liquid separator-   42 relay supercooled portion-   43 first flow rate control device-   44 bypass piping-   45 second flow rate control device-   46 first heat exchange part-   47 second heat exchange part-   50 distributor-   51 merger-   52 distribution merger-   60 first pressure detector-   61 second pressure detector-   100 first main pipe-   200 second main pipe-   300 a, 300 b, 300 c first branched pipe-   400 a, 400 b, 400 c second branched pipe-   500A, 500B first connection piping-   600A, 600B second connection piping-   700A, 700B branched pipe-   800A, 800B third connection piping-   900 main high-pressure gas pipe

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1

FIG. 1 is a diagram showing an entire configuration and the like of anair conditioning apparatus according to Embodiment 1. Firstly,descriptions will be given to means (a device) and the like constitutingan air conditioning apparatus 1 based on FIG. 1. The air conditioningapparatus 1 performs cooling and heating operations using arefrigeration cycle (heat pump cycle) by a refrigerant circulation.Especially, the air conditioning apparatus 1 is provided that it is adevice capable of performing a cooling-heating mixed operation thatsimultaneously performs the cooling and heating operations in aplurality of indoor units.

As shown in FIG. 1, the air conditioning apparatus 1 of the presentembodiment is mainly composed of a plurality of heat source apparatuses(heat source side unit, outdoor unit) 10A and 10B, a plurality of indoorunits (load side units) 20 a, 20 b, and 20 c, and a relay 30. In orderto control the refrigerant flow, a relay 30 is provided between heatsource apparatuses 10A and 10B and indoor units 20 a, 20 b, and 20 c tobe pipe-connected by various refrigerant piping. A plurality of indoorunits (load side units) 20, 20 b, and 20 c are connected so as to bearranged in parallel. In addition, when not be distinguished inparticular, refrigerator oil in the refrigerant will be also included inthe refrigerant in the explanations as follows. Also, for example, whenheat source apparatuses 10A and 10B and the like are not distinguishedor identified in particular, suffixes such as A and B will beabbreviated in the description hereinafter.

Between the heat source apparatus 10A and the relay 30 connect a set ofa first main pipe 100, a distributor 50, and a first connection piping500A and the set of a second main pipe 200, a merger 51, and a secondconnection piping 600A. In the same way, between the heat sourceapparatus 10B and the relay 30 connect a set of the first main pipe 100,the distributor 50, and the first connection piping 500B and the set ofthe second main pipe 200, the merger 51, and the second connectionpiping 600B. Then, in the set of the first main pipe 100, distributor50, and first connection piping 500, a low-pressure refrigerant flowsfrom the relay 30 side to the heat source apparatus 10 side. In the setof the second main pipe 200, the merger 51, and the second connectionpiping 600, a high-pressure refrigerant flows from the heat sourceapparatus 10 side to the relay 30 side.

Here, in the present embodiment, for example, it is provided that thedistributor 50 is installed inside the heat source apparatus 10A, thatis tubular distribution means having one inlet and a plurality ofoutlets. Because of this, the first connection piping 500A is inside theheat source apparatus A. The relation among the distributor 50, thefirst connection piping 500A, and the heat source apparatus A will bedescribed later. On the other hand, as for the tubular merger 51 havinga plurality of inlets and one outlet, the installation varies accordingto where heat source apparatuses 10A and 10B are installed. Therefore,basically, the merger 51 is installed outside the heat source apparatus10 and the refrigerant flowing in the second connection piping 600A and600B are made to be joined to flow into the second main pipe 200. Here,in the air conditioning apparatus according to the present embodiment, adiameter of the first main pipe 100 is larger than that of the secondmain pipe 200.

On the other hand, the relay 30 and the indoor unit 20 a are connectedby the second branched pipe 400 a and the first branched pipe 300 a. Inthe same way, the relay 30 and indoor unit 20 b are connected by thesecond branched pipe 400 b and the first branched pipe 300 b, and therelay 30 and indoor unit C are connected by the second branched pipe 400c and the first branched pipe 300 c. Through a piping connection by thefirst main pipe 100, second main pipe 200, second branched pipe 400 (400a, 400 b, and 400 c) and first branched pipe 300 (300 a, 300 b, and 300c), the refrigerant circulates among the heat source apparatuses 10A and10B, relay 30, indoor unit 20 a, 20 b, and 20 c to configure arefrigerant circuit.

In FIG. 1, the heat source apparatus 10 (10A and 10B) is configured byeach component as mentioned below. Here, the heat source apparatuses 10Aand 10B have almost the same configuration, so that descriptions will begiven to the heat source apparatus 10A. The compressor 11 (11A and 11B)pressurizes the sucked refrigerant to discharge it (send it out). It isnot limited in particular but the compressor 11 according to the presentembodiment is a capacity-variable inverter compressor implementing aninverter circuit (not shown). Therefore, for example, by freely changinga drive frequencies, which are larger than a minimum drive frequency, acapacity (refrigerant discharge amount per unit time) and cooling andheating capability (heat quantity per hour applied to the indoor unitside. Hereinafter, called as capability) accompanied thereby can bechanged. A four-way switching valve 12 (12A and 12B) is made to switch arefrigerant path by switching valves in accordance with the operation.In the present embodiment, path is made to be switched according to aall cooling operation (here, all indoor units under operation performcooling operation), cooling-dominant operation (cooling operationbecomes dominant in the cooling-heating mixed operation), and allheating operation (here, all indoor units in operation perform heatingoperation), heating-dominant operation (heating operation becomesdominant in the cooling-heating mixed operation).

A heat source apparatus side heat exchanger 13 (13A and 13B) has, forexample, a pipe for passing the refrigerant and a fin for increasing aheat transfer area of the refrigerant passing the pipe and the air(outdoor air) to perform heat exchange between the refrigerant and theair. For example, at the time of heating and heating-dominantoperations, the heat source apparatus side heat exchanger 13 functionsas an evaporator to evaporate the refrigerant into a gas. On thecontrary, when in the cooling and cooling-dominant operations, the heatexchanger 13 functions as a condenser to condense the refrigerant into aliquid. For example, at the time of the cooling-dominant operation, theheat exchanger 13 is adjusted to condense the refrigerant up to a stateof a two-phase region (gas liquid two-phase refrigerant) of a liquid anda gas. In the neighborhood of the heat source apparatus side heatexchanger 15, a heat source apparatus side fan (not shown) is providedfor efficiently performing heat exchange between the refrigerant and theair. An accumulator 14 (14A and 14B) accumulates an excessiverefrigerant in the refrigerant circuit.

There are provided a first check valve 15-1, second check valve 15-2,third check valve 15-3, and fourth check valve 15-4. Each check valvemakes a circulation path of the refrigerant that varies dependent on thecooling or heating operation fixed according to each operation andprevent the refrigerant to flow backward in the other paths. The firstcheck valve 15-1 (15-1A and 15-1B) is located between the heat sourceside heat exchanger 13 and the second main pipe 200 to allow arefrigerant circulation only in the direction from the heat source sideheat exchanger 13 to the second main pipe 200. The second check valve15-2 (15-2A and 15-2B) is located between the four-way switching valve12 and the first main pipe 100 to be mentioned later to allow arefrigerant circulation only in the direction from the first main pipe100 to the four-way switching valve 12. The third check valve 15-3(15-3A and 15-3B) is located between the four-way switching valve 12 andthe second main pipe 200 to allow a refrigerant circulation only in thedirection from the four-way switching valve 12 to the second main pipe200. The fourth check valve 15-4 (15-4A and 15-4B) is located betweenthe heat source apparatus side heat exchanger 13 and the first main pipe100 to allow a refrigerant circulation only in the direction from thefirst main pipe 100 to the heat source apparatus side heat exchanger 13.A first manual opening and closing valve 16-1 (16-1A and 16-1B) and asecond manual opening and closing valve 16-2 (16-2A and 16-2B) are in aclosed state, for example, at the time of shipment. Then, they areopened at the installation and made to circulate the refrigerant.Therefore, when operating the sir conditioning apparatus 1, they areusually in the open state.

The relay 30 in the present embodiment is composed of a first branchedpart 31, second branched part 36, gas-liquid separator 41, and relaysupercooled portion 42. The first branched part 31 has a first openingand closing valve 34 (34 a, 34 b, and 34 c), second opening and closingvalve 35 (35 a, 35 b, and 35 c), and association parts 32 and 33.

One ends of the first opening and closing valve 34 and the secondopening and closing valve 35 are connected with the first branched pipe300 respectively. Then, the other end of the first opening and closingvalve 34 is collectively connected by the association part 32 to connectwith the first main pipe 100. Further, the other end of the secondopening and closing valve 35 is collectively connected by theassociation part 33 to connect with the second main pipe 200 through thegas liquid separator 41. When flowing in the refrigerant from the indoorunit 20 to the first main pipe 100, the first opening and closing valve34 is opened and the second opening and closing valve 35 is closed. Whenflowing in the refrigerant from the second main pipe 200 to the indoorunit 20 through the gas-liquid separator 41, the first opening andclosing valve 34 is closed and the second opening and closing valve 35is opened.

A second branched part 36 has a first relay check valve 39 (39 a, 39 b,and 39 c), second relay check valve 40 (40 a, 40 b, and 40 c), andassociation parts 37 and 38. The first relay check valve 39 and thesecond relay check valve 40 are in a reverse parallel relation and eachend is connected with the second branched pipe, respectively. The otherend of the first relay check valve 39 is collectively connected by theassociation part 37. In the same way, the other end of the second relaycheck valve 40 is collectively connected by the association part 38.When the refrigerant flows from the indoor unit 20 side to the relaysupercooled portion 42 side, the flow passes the first relay check valve39 and the association part 37. When the refrigerant flows from therelay supercooled portion 42 side to the indoor unit 20 side, the flowpasses the second relay check valve 40 and the association part 38.

A gas-liquid separator 41 separates the refrigerant flowing from thesecond main pipe 200 into a gas refrigerant and a liquid refrigerant. Agas phase part (not shown) from which a gas refrigerant flows out isconnected with the first branched part 31 (association part 33). Whenthe second opening and closing valve 35 is open, the gas refrigerantflows into the indoor unit 20 side. On the other hand, the liquid phasepart (not shown) from which the liquid refrigerant flows out isconnected with the second branched part 36 through the relay supercooledportion 42.

The relay supercooled portion 42 has a first flow rate control device43, bypass piping 44, second flow rate control device 45, second heatexchange part 46, and first heat exchange part 47. The relay supercooledportion 42 is provided in order to overcool the liquid refrigerant, forexample, at the time of the cooling operation to supply it to the heatsource apparatus 10. The refrigerant and the like used for overcoolingis made to flow into the main pipe 100. The first flow rate controldevice 43 adjusts a refrigerant flow amount (a refrigerant amountflowing per unit time) flowing from the gas liquid separator 41 to thesecond branched part 36 through the first heat exchange part 47 andsecond heat exchange part 47. A bypass piping 47 connects the secondbranched part 36 with the main pipe 100 through the first heat exchangepart 47 and the second heat exchange part 46. The second flow ratecontrol device 45 adjusts the refrigerant flow amount passing throughthe bypass piping 44. The second heat exchange part 46 performs heatexchange between the refrigerant at the downstream part of the secondflow rate control device 45 flowing through the bypass piping 44 and therefrigerant flowing from the first flow rate control device 43 to theassociation part 38 of the second branched part 36. On the other hand,the first heat exchange part 47 performs heat exchange between therefrigerant flowing at the downstream part of the bypass piping 44 andthe second heat exchange part 46 and the refrigerant flowing from thegas-liquid separator 41 to the first flow rate control device 43.

A first pressure detector 60 and a second pressure detector 61 areattached to the relay 30. The first pressure detector 60 is attached tothe piping which connects the first flow rate control device 43 and thegas-liquid separator 41. The second pressure detector 61 is attached tothe piping which connects the first flow rate control device 43 and thesecond branched part 36.

Next, descriptions will be given to the configuration of the indoor unit20 (20 a, 20 b, and 20 c). The indoor unit 20 includes an indoor unitside heat exchanger 21 and an indoor unit side flow rate control device22 a adjacently connected in series with the indoor unit side heatexchanger 21. The indoor unit side heat exchanger 21 serves as anevaporator in the cooling operation and as a condenser in the heatingoperation like the above mentioned heat source apparatus side heatexchanger 13 to perform heat exchange between the air and therefrigerant in the air conditioning object space. The indoor unit sideflow rate control device 22 functions as a pressure reducing valve andexpansion valve to adjust the pressure of the refrigerant passing theindoor unit side heat exchanger 21. Here, the indoor unit side flow ratecontrol device 22 according to the present embodiment is composed of anelectronic expansion valve capable of changing an opening degree, forexample. Then, at the time of the cooling operation, based on a degreeof superheat at a refrigerant outlet side of the indoor unit side heatexchanger 21, an opening and closing status (opening degree) of theindoor unit side flow rate control device 22 is controlled. At the timeof the heating operation, based on the degree of supercooling degree atthe refrigerant outlet side (here, the second branched pipe 400), theopening and closing status (opening degree) of the indoor unit side flowrate control device 22 is controlled.

The air conditioning apparatus of the present embodiment that isconfigured as the above can perform operation of any of the four formsas mentioned the above: all cooling operation, all heating operation,cooling-dominant operation, and heating-dominant operation. Here, theheat source apparatus side heat exchanger 13 of the heat sourceapparatus 10 functions as a condenser at the time of the all coolingoperation and cooling-dominant operation and functions as an evaporatorat the time of the all heating operation and heating-dominant operation.

Next, descriptions will be given to the all cooling operation based onFIG. 1. Here, the case will be explained when all the indoor units 10perform the cooling operation. The flow direction of the refrigerant atthe all cooling operation is denoted by solid line arrows in FIG. 1.Here, descriptions will be given focusing on the heat source 10A. In theheat source apparatus 10A, the compressor 11A compresses a suckedrefrigerant to discharge a high-pressure gas refrigerant. Therefrigerant discharged from the compressor 11A flows into the heatsource apparatus side heat exchanger 13A through the four-way switchingvalve 12A. The high-pressure gas refrigerant is condensed through heatexchange while passing through the heat source side heat exchanger 13A.Then, the high-pressure gas refrigerant turns into a high-pressureliquid refrigerant to flow through a first check valve 15-1A and secondconnection piping 600A (because of the pressure of the refrigerant, itdoes not flow into a third check valve 15-3A and fourth check valve15-4A side). On the other hand, in the heat source apparatus 10B, therefrigerant flows through the second connection piping 600B in the sameway. The high-pressure liquid refrigerant flowed through the secondconnection piping 600A and second connection piping 600B merges in amerger 51 to flow into the relay 30 through by way of the second mainpipe 200.

A gas liquid separator 41 separates the refrigerant flowing into therelay 30 into a gas refrigerant and a liquid refrigerant. Here, in theall cooling operation, the refrigerant flowing into the relay 30 is theliquid refrigerant, almost no gas refrigerant basically. At the time ofthe heating operation, in the first branched part 31, the first openingand closing valve 34 (34 a, 34 b, and 34 c) is opened and the secondopening and closing valve 35 (35 a, 35 b, and 35 c) is closed.Therefore, no gas refrigerant flows in the indoor unit 20 (20 a, 20 b,and 20 c) side. On the other hand, the liquid refrigerant passes throughthe second heat exchange part 46 and first flow rate control device 43and part of it flows into the second branched part 36. The refrigerantflowed into the second branched part 36 branched into the indoor units20 a, 20 b, and 20 c through an association part 37, first relay checkvalves 39 a, 39 b, and 39 c, and second branched pipes 400 a, 400 b, and400 c.

In the indoor units 20 a, 20 b, and 20 c, the liquid refrigerant flowingfrom the second branched pipes 400 a, 400 b, and 400 c are subjected toan opening adjustment by the indoor unit side flow rate control devices22 a, 22 b, and 22 c to be pressure-adjusted. Here, as mentioned before,the opening adjustment by the indoor unit side flow rate control devices22 is performed based on the degree of superheat of each indoor unitside heat exchanger 21 at the refrigerant outlet side. Through theopening adjustment of each indoor unit side flow rate control device 22a, 22 b, and 22 c, the refrigerant turned into a low-pressure gas-liquidtwo-phase refrigerant or low-pressure liquid refrigerant flows into theindoor unit side heat exchangers 21 a, 21 b, and 21 c, respectively. Thelow-pressure gas-liquid two-phase refrigerant or low-pressure liquidrefrigerant evaporates through the heat exchange between the indoor airto be an air conditioning object space while passing through the indoorunit side heat exchangers 21 a, 21 b, and 21 c, respectively. Then, itturns into a low-pressure gas refrigerant to flow into the firstbranched pipes 300 a, 300 b, and 300 c, respectively. Thereby, it coolsthe indoor air through the heat exchange to perform the coolingoperation in the room. Here, the gas refrigerant is employed, however,in some cases, it may not be completely gasified in the indoor unit sideheat exchangers 21 a, 21 b, and 21 c and gas-liquid two-phaserefrigerant flows, for example, when the air conditioning load (heatamount required by the indoor unit, hereinafter, referred to as a load)in each indoor unit 20 is small and when a transient operation isperformed. The low-pressure gas refrigerant or gas-liquid two-phaserefrigerant (low-pressure refrigerant) flowing from the first branchedpipes 300 a, 300 b, and 300 c flow into the first main pipe 100 throughfirst opening and closing valves 34 a, 34 b, and 34 c and associationpart 32.

A distributor 50 divides the low-pressure refrigerant flowing in thefirst main pipe 100 into the refrigerant to flow into the heat sourceapparatus 10A side and the refrigerant to flow into the heat sourceapparatus 10B side. The refrigerant to flow into the heat sourceapparatus 10A side flows into the heat source apparatus 10A through thefirst connection piping 500A. Then, the refrigerant circulates byreturning to the compressor 11A again through the second check valve15-2A, four-way switching valve 12A, and accumulator 14A. Therefrigerant to flow into the heat source apparatus 10B flows into theheat source apparatus 10B side through the first connection piping 500Bas well. Then, the refrigerant returns back to the compressor 11Bthrough the second check valve 15-2B, four-way switching valve 12B, andaccumulator 14B of the heat source apparatus 10B. This is a circulationpath of the refrigerant at the time of the all, cooling operation.

Here, descriptions will be given to the refrigerant flow in the relaysupercooled portion 42. As mentioned before, the liquid refrigerantdivided by the gas-liquid separator partly flows into the secondbranched part 36 by way of the second heat exchange part 46 and thefirst flow rate control device 43. On the other hand, the refrigerantwhich does not flow into the second branched part 36 side passes throughthe bypass piping 14. Then, by adjusting the opening of the second flowrate control device 45, the refrigerant passes through the second heatexchange part 46 and the first heat exchange part 47 to supercool therefrigerant flowing into the second branched part 36 and flow into thefirst main pipe 100 as a low-pressure refrigerant. By supercooling therefrigerant, it is possible to reduce a enthalpy at the refrigerantinlet side (here, the second branched pipe 400 side) and increase theheat exchange amount with the air in the indoor unit side heatexchangers 21 a, 21 b, and 21 c. Here, when the opening of the secondflow rate control device 45 becomes large to increase the refrigerantamount (the refrigerant used for supercooling) flowing through thebypass piping 14, some refrigerant cannot be evaporated. In such a case,the gas-liquid two-phase refrigerant flows into the distributor 50through the first main pipe 100. In addition, the above holds not onlyfor the configuration of the air conditioning apparatus 1 of the presentembodiment. The same situations occur in the air conditioning apparatushaving a configuration such that a circuit bypassing a high-pressureliquid refrigerant with a low-pressure side is externally provided to aplurality of heat source apparatuses and a bypassed flow flows into theinlet side of the distribution part (the distributor 20 in the presentembodiment) for example.

FIG. 2 diagram showing a refrigerant flow at the time of the all heatingoperation according to Embodiment 1. Here, descriptions will be given toa case in which all indoor units 20 a, 20 b, and 20 c perform theheating operation. The refrigerant flow in the all heating operation isdenoted by solid line arrows in FIG. 2. Here, the heat source apparatus10A is mainly explained as well. In the heat source apparatus 10A, therefrigerant sucked by the compressor 11A is compressed and ahigh-pressure gas refrigerant is discharged. The refrigerant dischargedfrom the compressor 11A flows into the second connection piping 600Athrough the four-way switching valve 12A and check valve 15-3A (therefrigerant does not flow in the check valves 15-2A and 15-1A sidebecause of the refrigerant pressure). In the heat source apparatus 10B,the refrigerant flows in the second connection piping 600B based on thesimilar flow. The refrigerant flowing in the second connection piping600A and 600B are merged by the merger 51 to flow into the relay 30through the second main pipe 200.

The gas-liquid separator 41 separates the refrigerant flowed into therelay 30 into a gas refrigerant and a liquid refrigerant. The gasrefrigerant flowed into the relay 30 flows into the relay 30 flows intothe first branched part 31. Here, in the first branched part 31, thefirst opening and closing valve 34 (34 a, 34 b, and 34 c) is closed andsecond opening and closing valve 35 (35 a, 35 b, and 35 c) is opened.Therefore, the refrigerant flowed into the first branched part 31 isbranched to all indoor units 20 a, 20 b, and 20 c through theassociation part 33, second opening and closing valves 35 a, 35 b, and35 c, and first branched pipes 300 a, 300 b, and 300 c.

In the indoor units 20 a, 20 b, and 20 c, indoor unit side flow ratecontrol devices 22 a, 22 b, and 22 c adjust opening degree,respectively. Thus, regarding the refrigerant flowing from the firstbranched pipes 300 a, 300 b, and 300 c, the pressure of the refrigerantflowing in the indoor unit side heat exchangers 21 a, 21 b, and 21 c isadjusted, respectively. The high-pressure gas refrigerant is condensedthrough the heat exchange to turn into a liquid refrigerant whilepassing through the indoor unit side heat exchangers 21 a, 21 b, and 21c to pass through the indoor unit side flow rate control devices 22 a,22 b, and 22 c. Then, the indoor air is heated through the heat exchangeand heating operation is performed in the room. The refrigerant passingthrough the indoor unit side flow rate control devices 22 a, 22 b, and22 c turns into a low-pressure gas-liquid two-phase refrigerant orlow-pressure liquid refrigerant to flow into the association part 38through the second branched pipes 400 a, 400 b, and 400 c and secondrelay check valves 40 a, 40 b, and 40 c. Then, the refrigerant passesthrough the second heat exchange section 46 and first heat exchange part46 to flow into the first main pipe 100. Then, by adjusting the openingof the second flow rate control device 45, the low-pressure gas-liquidtwo-phase refrigerant flows into the first main pipe 100.

The distributor 20 divides the low-pressure refrigerant flowing in thefirst main pipe 100 into the refrigerant to flow into the heat sourceapparatus 10A side and the refrigerant to flow into the heat sourceapparatus 10B side. The refrigerant flowing at the heat source apparatus10A side flows into the heat source apparatus 10A through the firstconnection piping 500A and passes through the fourth check valve 15-4Aof the heat source apparatus 10A to flow into the heat source apparatusside heat exchanger 13A. While passing the heat source apparatus sideheat exchanger 13A, the refrigerant evaporates to become a gasrefrigerant through the heat exchange with the air. Then, therefrigerant returns to the compressor 11A again through the four-wayswitching valve 12A and accumulator 14A to circulate by being dischargedas described before. The same is true for the refrigerant flowing intothe heat source apparatus 10B side. The above is a circulation path ofthe refrigerant at the time of the all cooling operation.

Here, descriptions are given provided that in the above-mentioned allcooling operation and all heating operation, all indoor units 20 a, 20b, and 20 c perform operation, however, for example, part of the indoorunits may perform or stop operation. When part of the indoor units 20stops and the load is small for the entire air conditioning apparatus,either the compressor 11A or 11B of the heat source apparatuses 10A and10B may be stopped.

FIG. 3 is a diagram showing a refrigerant flow at the time of thecooling-dominant operation according to Embodiment 1. Here, descriptionswill be given to a case when the indoor units 20 a and 20 b perform thecooling operation and the indoor unit 20 c performs the heatingoperation. The refrigerant flow in the cooling-dominant operation isdenoted by solid line arrows in FIG. 3. Descriptions will be omitted forthe operations performed by the heat source apparatuses 10A and 10B andrefrigerant flow because they are the same as the all cooling operationexplained using FIG. 1. However, here, by controlling the condensationof the refrigerant in the heat source apparatus side heat exchangers 13Aand 13B, the refrigerant flowing into the relay 30 through the secondmain pipe 200 is made to be a gas-liquid two-phase refrigerant.

Descriptions will be omitted for the refrigerant flow in the coolingoperation by the indoor units 20 a and 20 b because they are the same asthe flow in the all cooling operation explained using FIG. 1. Here, theindoor unit 20 c performs the heating operation and the refrigerant flowis different from that of the indoor units 20 a and 20 b in the coolingoperation, therefore, the refrigerant flow is mainly explained. Firstly,the gas-liquid separator 41 divides the refrigerant flowed into therelay 30 into a gas refrigerant and a liquid refrigerant. Since in thefirst branched part 31, the first opening and closing valves 34 a and 34b are open and the second opening and closing valves 35 a and 35 b areclosed, the gas refrigerant does not flow into the indoor units 20 a and20 b sides. On the other hand, since the first opening and closingvalves 34 c is closed and the second opening and closing valves 35 c isopened, the gas refrigerant flows into the indoor unit 20 c side throughthe association part 33, second opening and closing valve 35 c, andfirst branched pipe 300 c.

In the indoor unit 20 c, the indoor unit side flow rate control device22 c adjusts the opening and regarding the refrigerant flowing from thefirst branched pipe 300 c, pressure adjustment is performed for therefrigerant flowing in the indoor unit side heat exchanger 21 c. Then,the high-pressure gas refrigerant is condensed into a liquid refrigerantwhile passing in the indoor unit side heat exchanger 21 c to passthrough the indoor unit side flow rate control device 22 c. Thereby, theindoor air is heated through the heat exchange and heating operation isperformed in the room. The liquid refrigerant passing the indoor unitside flow rate control device 22 c turns into a low-pressure liquidrefrigerant to flow into the association part 38 through the secondbranched pipe 400 c and second relay check valve 40 c. Thereafter, therefrigerant passes a branched part to the first flow rate control device15 and through the second heat exchanger part 46 to merge with therefrigerant at a downstream that flows from the gas liquid separator 41and passes the second flow rate control device 13. Then, the refrigerantflows into the indoor units 20 a and 20 b to turn into the refrigerantfor the cooling operation.

As mentioned above, in the cooling-dominant operation, the heat sourceapparatus side heat exchanger 13A of the heat source apparatus 10A andthe heat source apparatus side heat exchanger 13B of the heat sourceapparatus 10B become condensers. The refrigerant passing through theindoor unit 20 (here, the indoor unit 20 c) in the heating operation isused for the refrigerant for the indoor unit 20 (here, the indoor units20 a and 20 b) in the cooling operation. However, the loads in theindoor units 20 a and 20 b are small, so that when the refrigerantflowing in the indoor units 20 a and 20 b is suppressed, the opening ofthe first flow rate control device 15 is increased. Thus, therefrigerant passing through the indoor unit 20 c to flow into theassociation part 38 can be made to pass through the second heat exchangepart 46 and the first heat exchange part 47 and bypassed to flow intothe first main pipe 100. Then, through the first main pipe 100, agas-liquid two-phase refrigerant flows into the distributor 50.

FIG. 4 is a diagram showing the refrigerant flow at the heating-dominantoperation according to Embodiment 1. Here, descriptions will be given toa case when the indoor units 20 a and 20 b perform the heating operationand the indoor unit 20 c performs the cooling operation. The refrigerantflow in the cooling-dominant operation is denoted by solid line arrowsin FIG. 4. Descriptions will be omitted for the operations performed bythe heat source apparatuses 10A and 10B and the refrigerant flow becausethey are the same as the all heating operation explained using FIG. 2.

Descriptions will be omitted for the refrigerant flow in the heatingoperation by the indoor units 20 a and 20 b because they are the same asthe flow in the all heating operation explained using FIG. 2. Here, theindoor unit 20 c performs the cooling operation and refrigerant flow isdifferent from that of the indoor units 20 a and 20 b in the heatingoperation, therefore, the refrigerant flow is mainly explained. In theindoor units 20 a and 20 b, the refrigerant is condensed to turn into aliquid refrigerant through the heat exchange while passing through theindoor unit side heat exchangers 21 a and 21 b to pass through theassociation part 38 through the indoor unit side flow rate controldevices 22 a and 22 b. Then, the first flow rate control device 43 ismade to be closed state by the opening adjustment. Therefore, therefrigerant flow is suspended from the gas-liquid separator 41 and norefrigerant flows in the gas-liquid separator 41. Therefore, therefrigerant passing through the association part 18A flows into theindoor unit 20 c through the association part 37, the first relay checkvalve 39 c, and the second branched pipe 400 c by way of the second heatexchange part 46 to become a refrigerant for the cooling operation.

In the heating-dominant operation, the refrigerant output from theindoor unit (here, the indoor units 20 a and 20 b) in the heatingoperation flows in the indoor unit (here, the indoor units 20 c) in thecooling operation. Therefore, when the indoor unit in the coolingoperation stops, the amount of the gas-liquid two-phase refrigerantincreases flowing in the bypass piping 44. To the contrary, when theload increases in the indoor unit in the cooling operation, the amountof the gas-liquid two-phase refrigerant flowing in the bypass piping 44decreases. Therefore, while the refrigerant amount remains the samenecessary for the indoor unit 20 in the heating operation, the heatexchange processing capability changes of the indoor unit heat exchanger21 (evaporator) in the indoor unit 20 in the cooling operation. Then,capacities of the compressors 11A and 11B of the heat source apparatuses10A and 10B become the same.

A discharged refrigerant flow amount (mass flow mount) and suckedrefrigerant flow amount (mass flow mount) from each compressor 10 is thesame. Therefore, when the load of the indoor unit 20 in the coolingoperation under the heating-dominant operation changes, a dryness(density) of the low-pressure side refrigerant changes to keep aconstant mass flow, that is a gas-liquid two-phase refrigerant flowinginto the first main pipe 100 by way of the second flow rate controldevice 45. So that, the statuses of the refrigerant entering thedistributor 50 varies from a high dryness state to a low dryness stateeven if it is a gas-liquid two-phase refrigerant. In any condition,since compressors 11A and 11B continue to perform driving, therefrigerant needs to be branched in the distributor 50.

FIG. 5 is a diagram showing an installation status (arrangement) ofmeans focusing on the distributor 50 in Embodiment 1. Here, descriptionswill be given provided that the downward (in an actual installation, theground (the bottom face of the heat source apparatus 10) side) in FIG. 5is bottom and upside is up. FIG. 5 shows first manual opening andclosing valves 16-1A and 16-1B, second manual opening and closing valves16-2A and 16-2B, first main pipe 100, first connection piping 500A and500B, distributor 50, second main pipe 200, merger 51, and secondconnection piping 600A and 600B in the above-mentioned heat sourceapparatus 10A and 10B. Regarding the heat source apparatus 10A and 10B,part of the chassis is shown. Besides the above means, fixing sheetmetals 17 (17A and 17B) are shown in FIG. 5 as well, having a faceextending to almost upward perpendicular direction against the bottom ofthe heat source apparatus 10 and fixed. The fixing sheet metal 17A fixesthe first manual opening and closing valve 16-1A and second manualopening and closing valve 16-2A at a predetermined position. In the sameway, a fixing sheet metal 17B inside the heat source apparatus 10B fixespositions of the first manual opening and closing valve 16-1B and secondmanual opening and closing valve 16-2B.

FIG. 6 is an enlarged diagram of FIG. 5 with the distributor 50 beingthe center. As shown in FIG. 5, the distributor 50 is installed in thevicinity of the fixing sheet metal 17A inside the heat source apparatus10A. Here, the shape of the first connection piping 500A connecting thedistributor 50 with the first manual opening and closing valve 16-1A isspecified in advance. Therefore, the manual opening and closing valve16A in a fixed position in the heat source apparatus 10A and the firstconnection piping 500A whose shape is specified require an attachmentposition of the distributor 50 to be a fixed position (a specifiedposition) by necessity. Further, regarding the distributor 50, the sizeof the piping diameter and length at the refrigerant inlet is specifiedin advance and fixed thereto. Therefore, it is possible to define ashape by the specified size upon assuming distribution of therefrigerant and the like.

As shown in FIG. 5, the distributor 50 is arranged in such a way thatthe refrigerant inlet is oriented almost vertically downside and theoutlet for distributing the branched refrigerator is oriented almostvertically upside, the opposite direction. As a result, a bending parttoward upward in the heat source apparatus 10A is formed for the firstmain pipe 100 to be connected with the inlet of the distributor 50.Since two outlets are located at the same position against the ground(regarding their heights, outlet directions), there will be no imbalanceof the refrigerant in one outlet due to a gravity, so that therefrigerant can be distributed at a supposed predetermined distribution.

Two outlets of the distributor 50 and first connection piping 500A and500B are connected respectively. Here, descriptions will be given to theshape of the first connection piping 500A. The first connection piping500A of the present embodiment has a U-shaped bending part 501A for atone end part. In the case of an actual connection of the firstconnection piping 500A, the bending part 501A is made to be a reverseU-shaped and the first connection piping 500A is connected with thebending part 501A being the upper side than the inlet position of thedistributor 50. The first connection piping 500B has the bending part501B as well. Regarding at least the first connection piping 500A, theU-shaped bending part 502A is provided at the other end as well. Thebending part 502A is connected so that it is made to be a lower sidethan the connection part with the first manual opening and closing valve16-1A. By defining the shape of the first connection piping 500A inadvance, it is possible to specify the piping length, position, andattachment direction to the manual opening and closing valve 16-1A(compressor 11A) to fixedly dispose the distributor 50 at a specifiedposition.

Here, in the air conditioning apparatus 1 capable of performing acooling-heating mixed, operation like the present embodiment, the firstmain pipe 100 serves as returning piping in which the refrigerant alwaysreturns from the indoor unit 20 to the heat source apparatus 10 sideincluding the cooling-dominant operation and heating-dominant operation.Therefore, the refrigerant amount in the distributor 50 significantlychanges in an order such that all cooling operation>cooling-dominantoperation>heating-dominant operation, for example. Here, in the allcooling operation, a low-pressure gas or a high dryness gas refrigerantflows in the first main pipe 100. Then, since a refrigerant density issmall, there is a tendency that the refrigerant flow becomes faster. Thelarger the refrigerant flow amount and the longer the piping length,slower the performance due to a friction loss. Therefore, in order tolower a pressure loss at the maximum refrigerant flow amount, a pipingdiameter of the main pipe 100 is made large to lower the flow rate ofthe refrigerant. That allows an inlet diameter in the distributor 50 tobe large to lower the flow rate, as well. Here, a droplet (refrigerant,refrigerator oil) contained in the refrigerant is significantlysubjected to the gravity when a gas flow rate is lowered. Especially,when there is a bending part in the piping, no homogeneous massdistribution is available in a cross section inside the piping due to acentrifugal force.

A specified position assuming the above is predetermined in the relationwith the heat source apparatus 10A. In the air conditioning apparatus 1having a plurality of the heat source apparatuses 10 like the heatsource apparatuses 10A and 10B, specified members (the first connectionpiping 500A, in the present embodiment) for fixedly disposing thedistributor 50 are prepared. Using the specified members, thedistributor 50 is fixedly disposed so that its mounting positionincluding its orientation becomes always fixed against the heat sourceapparatus 10A independent of the installation location of the heatsource apparatuses 10A and 10B.

Thereby, it is possible to distribute the refrigerant amount flowingfrom the distributor 50 to the heat source apparatus 10A side inaccordance with a predetermined assumption. (That is, the refrigerantflowing in another heat source apparatus 10B side becomes stable.) Sincedistribution based on a predetermined assumption is possible, forexample, in the heat source apparatuses 10A and 10B, even when a slightdifference in the distribution should occur, a product specification canbe made in response thereto at the product development stage. Forexample, it is possible to correspond in such a way that a difference isprovided in the refrigerant flow amount of the compressors 11A and 11Bto change a return ratio of the liquid refrigerant.

It is considered that in the air conditioning apparatus 1 capable ofperforming a cooling-heating mixed operation, for example, whenperforming the cooling-dominant and heating-dominant operations in whatis called an intermediate stage such as spring and autumn, therefrigerant flow amount returning to the distributor 50 becomes small.Then, since in the indoor unit 20 in the cooling operation the loadbecomes small, the refrigerant does not completely evaporate and turnsinto a gas-liquid two-phase refrigerant to flow in the first main pipe100. As mentioned the above, by fixedly disposing the distributor 50,for example, it is possible to uniformly distribute the liquidrefrigerant, leading to a proper distribution effect of the refrigerant.Especially in the air conditioning apparatus 1 capable of performing acooling-heating mixed operation, the cooling operation frequently occurshi the intermediate stage. As a result, problems related to liquiddistribution in the distributor 50 easily to happen, however, thefixedly disposed distributor may contribute toward solving the problems.

In the present embodiment, compressors 11A and 11B are acapacity-variable inverter compressor. When at least either of them is acapacity-variable compressor 11, the refrigerant flow amountsignificantly varies among a plurality of compressors 11. Even in such acase, it is possible to determine a specified position for thedistributor 50 by adopting measures for the difference in therefrigerant flow amount at the product development stage. Further, byfixedly disposing the distributor 50 at the specified position,variation conditions of the liquid refrigerant distribution inaccordance with the change in the refrigerant flow amount in the bothcompressors 11 can be stabilized. For example, by changing the pipingdiameter of the first connection piping 500A and 500B after thedistributor 50, the distribution amount can be varied. In addition, theshape (length, diameter, and number of bending) of the first connectionpiping 500A provided inside the heat source apparatus 10A can bedifferent from that of the first connection piping 500B. Thus, assumingthe distribution amount of the liquid along with the distributor 50 isfacilitated.

In the above descriptions, all the indoor units 20A are made to performthe cooling or heating operation, however, in some cases, only part ofthe indoor units 20 perform operation, for example. In such a case,since the load of the indoor unit 20 side is often small, all the heatsource apparatuses 10 need not to be driven (the compressor 11 isdriven), and sometimes part of them can be stopped. Therefore, it isconsidered that the heat source apparatus 10A (compressor 11A) is inoperation and the heat source apparatus 10B (compressor 11B) is stopped.Basically, in many cases the load in the indoor unit 10 is small, thereis a strong possibility that the refrigerant flowing through the mainpipe 100 into the distributor 50 is a gas-liquid two-phase refrigerant.As mentioned the above, the liquid (liquid refrigerant) becomes astratified flow flowing along the internal face of the piping to besubjected to gravity and centrifugal forces.

Typically, since the compressor 11B is stopped and no pressure relatedsuction is generated at the first connection piping 500B side, no gasrefrigerant flows. Here, in the air conditioning apparatus 1 accordingto the present embodiment, the distributor 50 is fixedly disposed sothat the inlet is located at the lower side of the outlet. Accordingly,the liquid refrigerant turns into a stratified flow to flow along theinternal face of the piping from downward to upward. The liquidrefrigerant is heavier than the gas refrigerant, it has momentum.Therefore, there is a possibility that even if no gas refrigerant flows,the liquid refrigerant may try to flow into the first connection piping500B side.

As mentioned the above, the first connection piping 500B according tothe present embodiment extends further upward from the distributor 50,as mentioned before, to have a bending part 501B. As a result, theliquid refrigerant that tried to flow in the first connection piping500B side is subjected to gravity, and rapidly stalls, falls downward toreturn back to the distributor 50. Therefore, it is possible to preventthe refrigerant to be supplied with the indoor unit 20 side from notreturning back to the compressor 11 by that no refrigerant flows in thefirst connection piping 500B side. In addition, the first connectionpiping 500A also has a bending part 501A, however, since a force relatedto suction of the compressor 11A is exerted, the liquid refrigerantflows into the first connection piping 500A.

That holds to a case in which not only the liquid refrigerant but alsothe refrigerator oil flowed out of the compressor 11 returns backthrough each refrigerant piping, indoor unit 20, and the like.Therefore, no refrigerator oil flows toward the first connection piping500B of the heat source apparatus 10 side that is not in operation, sothat the compressor 11A in operation no longer becomes an oil-depletedstate.

In the first main pipe 100, the refrigerant always flows in thedirection from the indoor unit 20 side to the heat source apparatus 10side. Therefore, when the refrigerant flow amount is small, especiallythe refrigerator oil cannot reach the distributor 50 while being carriedby the flow, so that it is feared that the refrigerant may beaccumulated before the distributor 50. An internal flow in the main pipe100 will not be reversed, that is no refrigerant flows from the heatsource apparatuses 10A and 10B side to the indoor unit 20 side. As aresult, there is a possibility that the accumulated oil may continue tostay by the time when the refrigerant flow amount becomes larger. As fora method to return the accumulated oil, there is a method such that bydeliberately increasing the refrigerant flow amount, the refrigeratoroil is pushed out to pass the distributor 50, for example. Anothermethod is that the liquid refrigerant having a low viscosity is made toflow from the indoor unit 20 side intentionally, and by dissolving therefrigerator oil into the liquid refrigerant to lower the viscosity, itbecomes easier for the refrigerant oil to advance in the distributor 50.In any case, the droplet has to be separated upon reaching thedistributor 50. By fixedly disposing the distributor 50 at a specifiedposition, its posture can be fixed according to a predetermined manner.It is possible to keep the refrigerant flow amount for returning therefrigerator oil and liquid refrigerant amount to be returned at aminimum amount as assumed. Therefore, a stable air conditioning ispossible without excessively changing the refrigeration cycle operation.

Embodiment 2

FIG. 7 is a diagram showing an entire configuration of the airconditioning apparatus according to Embodiment 2. In FIG. 7,descriptions will be omitted for those having the same numerals andsymbols as in FIG. 1, because their operations will be the same as whatis described in Embodiment 1. Here, the heat source apparatuses 10 (10Aand 10B) according to Embodiment 2 has a branched pipe 700 (700A and700B) being branched from a discharged side piping connecting thefour-way switching valve 12 and the discharging side of the compressor11. A third manual opening and closing valve 16-3 (16-3A and 16-3B) isprovided on the branched pipe 700. Like the first manual opening andclosing valve 16-1 and the second manual opening and closing valve 16-2,for example, the third manual opening and closing valve is closed whenshipping and opened at the time of installation. An electromagneticopening and closing valve 18 (18A and 18B) is located between the manualopening and closing valve 16-3 and the compressor 11 on the branchedpipe 700. When the electromagnetic opening and closing valve 18 is open,the refrigerant passes through the branched pipe 700, and when closed,no refrigerant passes. A flow rate control valve 19 (19A and 19B)adjusts the refrigerant flow amount flowing between the heat sourceapparatus side heat exchanger 13 and the manual opening and closingvalve 15.

A distribution merger 52 functions as a merger for merging therefrigerant like the merger 51 at the time of the all cooling operationand cooling-dominant operation when the heat source apparatus side heatexchanger 13 functions as a condenser. At the time of the all heatingoperation and heating-dominant operation when the heat source apparatusside heat exchanger 13A functions as an evaporator, the distributionmerger 52 functions as a distributor for distributing the refrigerantlike the distributor 50. Here, it is not limited in particular,although, since the distribution merger 52 functions as a distributor aswell, its shape can be the same as that of the distributor 50 describedin Embodiment 1. The distribution merger 52 can be provided in the heatsource apparatus 10A like the distributor 50. Here, it is provided inthe heat source apparatus 10A. Therefore, a third connection piping 800Ais provided in the heat source apparatus 10A as well. Its shape ispredetermined like the first connection piping 500A. Thereby, theinstallation position of the distribution merger 52 in the heat sourceapparatus 10A is a fixed position (provision). On the other hand, thethird connection piping 800B is connected to the manual opening andclosing valve 15B inside the heat source apparatus 10B again after goingout the heat source apparatus 10A once in order to connect to thedistribution merger 52 in the heat source apparatus 10A.

A main high-pressure gas pipe 900 is connected to a branched pipe 700(the manual opening and closing valve 16-3) through the merger 51 andthe second connection piping 600 and the discharged gas refrigerantflows therein. In the present embodiment, the merger 51 is installedoutside the heat source apparatuses 10A and 10B.

Next, descriptions will be given to the all cooling operation based onFIG. 7. Here, a case will be explained in which all the indoor units 20a, 20 b, and 20 c perform the cooling operation. The refrigerant flow inthe all cooling operation is shown by solid line arrows in FIG. 7. Here,descriptions will be given focusing on the heat source apparatus 10A. Inthe heat source apparatus 10A, the compressor 11A compresses the suckedrefrigerant to discharge a high-pressure gas refrigerant. Therefrigerant discharged from the compressor 11A flows into the heatsource apparatus side heat exchanger 13A through the four-way switchingvalve 12A. On the other hand, since the electromagnetic opening andclosing valve 18A is closed at the time of the all cooling operation, norefrigerant flows in the main high-pressure gas pipe 900.

The high-pressure refrigerant flowing into the heat source apparatusside heat exchanger 13A is condensed through the heat exchange whilepassing the heat source apparatus side heat exchanger 13A and turns intoa high-pressure liquid refrigerant to flow into the third connectionpiping 800A through the flow rate control valve 19A. On the other hand,in the heat source apparatus 10B, the refrigerant flows in the thirdconnection piping 800B in accordance with a similar flow. Therefrigerant passing the third connection piping 800A and thirdconnection piping 800B merges in the distribution merger 52 to bebranched into the indoor units 20 a, 20 b, and 20 c by way of the secondmain pipe 200.

In the indoor units 20 a, 20 b, and 20 c, the indoor unit side flow ratecontrol devices 22 a, 22 b, and 22 c adjust the pressure of the liquidrefrigerant flowing from the second branched pipe 400 a, 400 b, and 400c by adjusting the opening, respectively. The opening adjustment of eachindoor unit side flow rate control device 22 is performed based on adegree of superheat at a refrigerant outlet side of the indoor unit sideheat exchanger 21. Through the opening adjustment by each indoor unitside flow rate control devices 22 a, 22 b, and 22 c, the refrigerantturned into a low-pressure gas-liquid two-phase refrigerant orlow-pressure liquid refrigerant flows into the indoor unit side heatexchangers 21 a, 21 b, and 21 c, respectively. The low-pressuregas-liquid two-phase refrigerant or low-pressure liquid refrigerantevaporates through the heat exchange with the indoor air while passingthe indoor unit side heat exchangers 21 a, 21 b, and 21 c respectivelyto turn into a low-pressure gas refrigerant or gas-liquid two-phaserefrigerant. Then, they flow into the first branched pipes 300 a, 300 b,and 300 c, respectively. Then, it cools the indoor air through heatexchange to perform cooling operation in the room. At the time of theall cooling operation, all the first opening and closing valves areopened and all the second opening and closing valves 35 are closed inthe first branched part 31. As a result, the low-pressure gasrefrigerant or gas-liquid two-phase refrigerant (low-pressurerefrigerant) flowing from the first branched pipes 300 a, 300 b, and 300c flows into the first main pipe 100 through the first opening andclosing valves 34 a, 34 b, and 34 c and the association part 32.

The distributor 50 divides the low-pressure refrigerant flowing in themain pipe 100 into the refrigerant flowing in the heat source apparatus10A side and the refrigerant flowing in the heat source apparatus 10Bside. The refrigerant flowing in the heat source apparatus 10A sidecirculates by flowing into the heat source apparatus 10A through thefirst connection piping 500A, passing the accumulator 14A of the heatsource apparatus 10A, returning back to the compressor 11A, and beingdischarged as mentioned before. That makes a circulation path at thetime of the cooling operation in a refrigerant main circuit. Therefrigerant flowing into the heat source apparatus 10B flows into theheat source apparatus 10B through the first connection piping 500B toreturn back to the compressor 11B through the accumulator 14B of theheat source apparatus 10B in the same way.

Next, descriptions will be given to the all heating operation based onFIG. 8. Here, a case will be explained in which all the indoor units 20a, 20 b, and 20 c perform the cooling operation. The refrigerant flow inthe all cooling operation is shown by the solid line arrows in FIG. 8.Here, descriptions will be given focusing on the heat source apparatus10A. Firstly, using the four-way switching valve 12A, switching isperformed so as to connect the heat source apparatus side heat exchanger13A and accumulator 14A. On the other hand, the valve is dosed for therefrigerant discharged from the compressor 11A not to pass the four-wayswitching valve 12A. The electromagnetic opening and closing valve 16Ais opened for the refrigerant to flow into the main high-pressure gaspipe 900 through the branched pipe 700A, second connection piping 600A,and merger 51. Means corresponded by the heat source apparatus 10B isthe same.

In the heat source apparatus 10A, the compressor 11A compresses thesucked refrigerant to discharge a high-pressure gas refrigerant. Thedischarged refrigerant from the compressor 11A flows into the secondconnection piping 600A through the branched pipe 700A andelectromagnetic opening and closing valve 18A. In the heat sourceapparatus 10B, there is a refrigerant flow into the second connectionpiping 600B. The refrigerants flowing in the second connection piping600A and the second connection piping 600B are merged by the merger 51to flow into the first branched part 31 by way of the main high-pressuregas pipe 900. In the all heating operation, all the first opening andclosing valves 34 are dosed and all the second opening and closingvalves 35 are opened in the first branched part 31. The refrigerantflowing into the first branched part 31 is branched into the indoorunits 20 a, 20 b, and 20 c through the association part 33, the secondopening and dosing valves 35 a, 35 b, and 35 c, and the first branchedpipes 300 a, 300 b, and 300 c.

In the indoor units 20 a, 20 b, and 20 c, indoor unit side flow ratecontrol devices 22 a, 22 b, and 22 c perform opening control, and forthe refrigerants flowing from the first branched pipes 300 a, 300 b, and300 c, respectively, pressure is adjusted when flowing in the indoorunit side heat exchanger 21. The high-pressure gas refrigerant iscondensed through the heat exchange while passing the indoor unit sideheat exchangers 21 a, 21 b, and 21 c and turns into a high-pressureliquid refrigerant to pass indoor unit side flow rate control devices 22a, 22 b, and 22 c. Thereby, indoor air is heated by heat exchange andheating operation is performed in the room. The refrigerant passing theindoor unit side flow rate control devices 22 a, 22 b, and 22 c turnsinto a low-pressure gas-liquid two-phase refrigerant or low-pressureliquid refrigerant to flow into the second main pipe 200 through thesecond branched pipes 400 a, 400 b, and 400 c.

The distribution merger 52 divides the low-pressure refrigerant flowingin the second main pipe 200 into the refrigerant to flow in the heatsource apparatus WA side and the refrigerant to flow in the heat sourceapparatus 10B side. The refrigerant flowing in the heat source apparatus10A side flows into the heat source apparatus 10A through the thirdconnection piping 800A. Then, the refrigerant circulates by passing theheat source apparatus side heat exchanger 13A, four-way switching valve12A, accumulator 14A, returning back to the compressor 11A, and beingdischarged as mentioned the above. That is a circulation path at thetime of the heating operation. Here, since the heat source apparatusside heat exchanger 13A functions as an evaporator in the all heatingoperation, the refrigerant gasifies through heat exchange. Therefrigerant flows in the heat source apparatus 10B flows into the heatsource apparatus 10B through the third connection piping 800B in thesame way. Then, the refrigerant returns back to the compressor 11B byway of the heat source apparatus side heat exchanger 13B, four-wayswitching valve 12B, and accumulator 14B of the heat source apparatus10B of the heat source apparatus 10B.

Here, in the present embodiment, descriptions are given provided that inthe all cooling operation and all heating operation described above, allindoor units A, B, and C are in operation, however, some indoor unitsmay be in operation while others are stopped. For example, when someindoor units are stopped and the load is small for the entire airconditioning apparatus, either of the compressor 11A or 11B of the heatsource apparatus 10A or 10B may be stopped.

FIG. 9 is a diagram showing a refrigerant flow in the cooling-dominantoperation according to Embodiment 2. Here, descriptions will be given toa case in which the indoor units 20 a and 20 b perform the coolingoperation and the indoor unit 20 c performs the heating operation. Therefrigerant flow in the cooling-dominant operation is shown by the solidline arrows in FIG. 9. As for the operation performed by the heat sourceapparatuses 10A and 10B and refrigerant flow, descriptions will beomitted for the same part with the all cooling operation becauseexplanations are the same as those using FIG. 7.

On the other hand, in the cooling-dominant operation, since unlike theall cooling operation, the gas refrigerant is supplied with the indoorunit (here, the indoor unit C) performing the heating operation, theelectromagnetic opening and closing valve 18A is opened in the heatsource apparatuses 10A. Thereby, part of the high-pressure gasrefrigerant flows into the first branched part 31 through the branchedpipe 700, second connection piping 600A, and merger 51. Here, when theload based on the heating operation is small, the electromagneticopening and closing valve 18B of the heat source apparatuses 10B may beclosed. On the other hand, when the load of the indoor unit 20 in theheating operation is large, the electromagnetic opening and closingvalve 18B may be opened in the heat source apparatuses 10B as well andthe high-pressure gas refrigerant may be supplied from the heat sourceapparatuses 10B side.

Descriptions will be omitted for the refrigerant flow in the indoorunits 20 a and 20 b in the cooling operation because it is the same asthose in the all cooling operation explained using FIG. 7, so that theheating operation of the indoor unit 20 c will be explained. Here, inthe first branched part 31, no gas refrigerant flows in the indoor units20 a and 20 b side because the first opening and dosing valves 34 a and34 b are opened and the second opening and dosing valves 35 a and 35 bare closed. On the other hand, since the first opening and closingvalves 34 c is closed and the second opening and closing valves 35 c isopened, the gas refrigerant flows in the indoor unit 20 c side throughthe association part 33A, second opening and closing valves 35 c, andfirst branched pipe 300 c.

In the indoor unit C, the indoor unit side flow rate control device 22 cperforms the opening adjustment and regarding the refrigerant flowingfrom the first branched pipe 300 c, the pressure of the refrigerant isadjusted that flows in the indoor unit side heat exchanger 21 c. Then,the high-pressure refrigerant is condensed and turns into a liquidrefrigerant through heat exchange while passing the indoor unit sideheat exchanger 21 c to pass the indoor unit side flow rate controldevice 22 c. Thereby, the indoor air is heated through heat exchange andthe heating operation is performed in the room. The refrigerant passingthe indoor unit side flow rate control device 22 c turns into a littledecompressed low-pressure refrigerant to pass the second branched pipe400 c. Then, the refrigerant merges with the refrigerant flowing in thesecond main pipe 200 and flows into the indoor units 20 a and 20 b toturn into a refrigerant for the cooling operation. As for the flow andoperation of each means thereafter of the refrigerant for the coolingoperation, descriptions will be omitted because they are the same as theflow of the all cooling operation explained using FIG. 7.

FIG. 10 is a diagram showing a refrigerant flow in the heating-dominantoperation according to Embodiment 2. Here, descriptions will be given toa case in which the indoor units 20 b and 20 c perform the heatingoperation and the indoor unit 20 a performs the cooling operation. Therefrigerant flow in the cooling-dominant operation is shown by the solidline arrows in FIG. 10. As for the operation performed by the heatsource apparatuses 10A and 10B and refrigerant flow, descriptions willbe omitted because explanations are the same as the all coolingoperation explained using FIG. 8.

As for the refrigerant flow in the heating operation of the indoor units20 b and 20 c, descriptions will be omitted because it is the same asthe flow of the all heating operation. Here, the indoor unit 20 aperforms the cooling operation, and since the refrigerant flow isdifferent from the indoor units 20 b and 20 c in the heating operation,descriptions will be given focusing the flow. In the indoor units B andC, the refrigerant is condensed into a liquid refrigerant through theheat exchange while passing the indoor unit side heat exchangers 21 aand 21 b to flow into the second branched pipes 400 b and 400 c throughthe indoor unit side flow rate control devices 22 a and 22 b.

Most of the refrigerant flowing in the second branched pipes 400 b and400 c passes through the second main pipe 200 to flow into the heatsource apparatuses 10A and 10B through the distribution merger 52. Partof the refrigerant flows into the indoor, unit A by way of the secondbranched pipe 400 a to turn into a refrigerant for the coolingoperation. Through the heat exchange of the indoor unit side heatexchanger 21 a of the indoor unit A, the gasified gas refrigerant orgas-liquid two-phase refrigerant flows into the first main pipe 100through the first branched pipe 300 a and opening and closing valve 8 a.The distributor 50 distributes a low-pressure refrigerant flowing in thefirst main pipe 100. Each divided refrigerant by the distribution flowsinto the heat source apparatus 10 to return back to the compressor 11through the accumulator 14 of the heat source apparatuses 10.

Here, the distributor 50 and a joining branch part 25 are provided toconnect to the first connection piping 500A and third connection piping800 A whose shapes are provided in advance. Therefore, the same effectas Embodiment 1 can be obtained.

Embodiment 3

FIG. 11 is a diagram showing an entire configuration of the airconditioning apparatus 1 according to Embodiment 3. FIG. 11 differs fromFIG. 1 in that the distributor 50 is provided outside the heat sourceapparatus 1A. Like FIG. 11, as for a location where the distributor 50or distribution merger 52 is installed, it is not limited to in the heatsource apparatus 1A in particular. It can be fixed at a predeterminedlocation outside the heat source apparatus 1A by the first connectionpiping 500A whose shape is provided in advance like Embodiment 1 asmentioned the above.

In Embodiment 1, the distributor 50 is fixedly disposed inside the heatsource apparatus 10A by the first connection piping 500A, however, it isnot limited thereto. For example, the distributor 50 may be fixedlydisposed at the heat source apparatus 10B side. It goes without sayingthat when only the location where the distributor 50 is fixedly disposedis specified, the same effect can be observed by fixing it in the heatsource apparatus 10A through a fixing sheet metal 17A and the like.

The distributor 50 can be fixedly built-in inside the heat sourceapparatus 10A in advance to be shipped into the market. Thereby; thereis an advantage that an installation time can be reduced on the site. Onthe other hand, when not built-in, it is necessary to install it on thesite. However, no distributor is required when a device is composed ofonly one heat source apparatus 10A, the heat source apparatus can beshared between a device having a plurality of heat source apparatusesand a device having a single heat source apparatus, so that aninstallation-flexible product can be obtained.

Embodiment 4

In the embodiment above, descriptions are given to the air conditioningapparatus 1 in which a heat source apparatus 10A and heat sourceapparatus 10B are provided, however, the number of the heat sourceapparatus is not limited to two. It goes without saying that in a deviceconfiguration having three or more heat source apparatuses 10, by fixingthe distributor 50 at a predetermined location in part of the heatsource apparatuses 10, an effect is the same on a refrigerantdistribution to the heat source apparatus.

Like the embodiment above, the present invention has a main pipe inwhich the refrigerant flows in one direction from the indoor unit 20 tothe heat source apparatus 10 side, so that it is effective for a devicewhere the refrigerant flow amount changes, however, it is not limitedthereto. For example, the present invention is applicable to otherrefrigeration cycle such as a refrigeration device.

1. An air conditioning apparatus comprising: a plurality of heat sourceapparatuses having a heat source apparatus side heat exchanger and acompressor, one or plurality of indoor units having a flow rate controldevice and an indoor unit side heat exchanger, at least two main pipesfor pipe-connecting between said plurality of heat source apparatusesand one or plurality of indoor units, a tubular distributor forbranching a refrigerant from said main pipe flowing from an inlet into aplurality of outlets to distribute into said plurality of heat sourceapparatuses, and connection piping for connecting said plurality of heatsource apparatuses and said distributor respectively, wherein saiddistributor is fixedly disposed against one heat source apparatus amongsaid plurality of heat source apparatuses at a predetermined positionand in a predetermined direction.
 2. The air conditioning apparatus ofclaim 1, wherein said air conditioning apparatus is an air conditioningapparatus capable of cooling-heating mixed operation to circulate therefrigerant in said plurality of indoor units to simultaneously performboth the heating operation and cooling operation, and among said mainpipes, the main pipe in which the refrigerant returns from said indoorunit to said heat source apparatus at the time of said cooling-heatingmixed operation and said distributor are connected.
 3. The airconditioning apparatus of claim 1, wherein said air conditioningapparatus is an air conditioning apparatus capable of cooling-heatingmixed operation to circulate the refrigerant in said plurality of indoorunits to simultaneously perform both the heating operation and coolingoperation, and among said main pipes, the main pipe in which saidrefrigerant flows only in a direction where the refrigerant flows fromsaid plurality of indoor units to said plurality of heat sourceapparatuses regardless of the cooling operation or heating operation andsaid distributor are connected.
 4. The air conditioning apparatus ofclaim 1, wherein through said connection piping having a predeterminedshape, said one heat source apparatus and said distributor areconnected.
 5. The air conditioning apparatus of claim 4, wherein saidconnection piping has a configuration such that a U-shaped bending partis formed at an upper location than a connection part with saiddistributor.
 6. The air conditioning apparatus of claim 1, wherein saiddistributor is fixedly disposed in such a way that said inlet is locatedat a ground side to said outlet.
 7. The air conditioning apparatus ofclaim 1, wherein a piping diameter of said distributor at a refrigerantinlet side is fixed to a predetermined size.
 8. The air conditioningapparatus of claim 1, wherein a piping length of said distributor at arefrigerant inlet side is fixed to a predetermined size.
 9. The airconditioning apparatus of claim 1, wherein a refrigerant inlet of saiddistributor is disposed facing perpendicularly downward.
 10. The airconditioning apparatus of claim 1, wherein a refrigerant outlet of saiddistributor is disposed facing perpendicularly upward.
 11. The airconditioning apparatus of claim 1, wherein the refrigerant outlet ofsaid distributor is disposed at the same location against the ground.12. The air conditioning apparatus of claim 2, wherein through saidconnection piping having a predetermined shape, said one heat sourceapparatus and said distributor are connected.
 13. The air conditioningapparatus of claim 3, wherein through said connection piping having apredetermined shape, said one heat source apparatus and said distributorare connected.
 14. The air conditioning apparatus of claim 12, whereinsaid connection piping has a configuration such that a U-shaped bendingpart is formed at an upper location than a connection part with saiddistributor.
 15. The air conditioning apparatus of claim 13, whereinsaid connection piping has a configuration such that a U-shaped bendingpart is formed at an upper location than a connection part with saiddistributor.
 16. The air conditioning apparatus of claim 2, wherein saiddistributor is fixedly disposed in such a way that said inlet is locatedat a ground side to said outlet.
 17. The air conditioning apparatus ofclaim 3, wherein said distributor is fixedly disposed in such a way thatsaid inlet is located at a ground side to said outlet.
 18. The airconditioning apparatus of claim 2, wherein a refrigerant inlet of saiddistributor is disposed facing perpendicularly downward.
 19. The airconditioning apparatus of claim 3, wherein a refrigerant inlet of saiddistributor is disposed facing perpendicularly downward.